Musical instrument employing continuously moving members



Feb. 19, 1952 A. F. KNOBLAUGH ,6 4

MUSICAL INSTRUMENT EMPLOYING CONTINUOUSLY MOVING MEMBER Filed July 20, 1948 2 SHEETS-SHEET 1 MWIAWOEMDZ/l IN VEN TOR.

M G la/7 A. F. KNOBLAUGH MUSICAL INSTRUMENT EMPLOYING 2 SHEETSSHEET 2 Feb. 19, 1952 CONTINUOUSLY MOVING MEMBER Filed July 20, 1948 INVENTOR.

walla 1w Patented Feb. 19 1952 MUSICAL INSTRUMENT EMPLOYING CON- TINUOUSLY MOVING MEMBERS Armand F. Knoblaugh, Cincinnati, Ohio, assignor to The Baldwin Company, Cincinnati, Ohio, a

corporation of Ohio Application July 20, 1948, Serial No. 39,674

13 Claims. 1

My invention relates generally to musical instruments, and particularly to electrical musical instruments employing continuously moving members having a plurality of series of light openings, magnetic projections or other elements, the rate of passage of which past a given point or point determines the musical pitch or frequency of the tones produced.

In such instruments, wherein a whole gamut of pitch determining elements is disposed upon one moving member in an endeavorto provide a structure of practical size, cost, and operation, there is a problem of providing an applicable series of whole number for proportioning the quantities of elements in respective endless rows disposed on a disc, drum, endless tape, or the like. The quantities must be so selected that rates of passage of the elements in the various rows will approximate the frequencies or pitches or respective notes of the equally tempered scale closely enough so that satisfactory musical results may be obtained.

The problem contains two opposing difliculties. On one hand the individual members of elements in a series must be high enough so that their relationships can approximate that of the notes of the equally tempered scale. On the other hand, the numbers must be low enough so that in placing series of elements on a practical size moving device, the spacing of the elements in a series member must be sufiiciently generous so that inaccuracies of spacing do not deteriorate the musical effects obtained. As an example, "noise in the musical tones is commensurate with proportionate inaccuracy of spacing. Such proportionate inaccuracy, in any practical fabrication and construction, increases as the space between adjacent elements decreases, thus dictating that the numbers of elements be low, and thus the space between them be large.

Another aspect of the. problem relates to an instrument producing complex tones by the scanning of wave forms by elements as above, in motion. In such an instrument wherein one element completely scans a wave form before an adjacent element carries out its scanning, only sufiicient spacing of elements obtained by using low numbers of elements, will permit use of adequate size wave forms so that desired wave forms. may be incorporated and satisfactory replicas as musical tones obtained.

' Consequently, a primary object of my invention is to provide a relationship of pitch determining elements in musical instruments, so that between the pitch determining elements and the wave form patterns in musical instruments of the photoelectric type wherein beams of light scan such patterns to produce in a photocell circuit electric pulsations corresponding to the tones desired.

It is a further object to provide, on a single compact moving member, means for determining the pitch of a gamut of tones in photoelectric or other musical instruments.

As a supplement to the above objects, since it is sometimes desirable in a musical instrument to employ more than one moving member, an object of the present invention is to provide compact pitch means comprising two moving members and associated elements.

These and other objects of my invention which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that construction and arrangement of parts and in those procedures of which I shall now describe exemplary embodiments. Reference is made to the accompanying drawings wherein:

Figure 1 is a diagrammatic representation of elements of a photoelectric musical instrument to which my invention may be applied;

Figure 2 shows a portion of a pitch disc and associated part embodying my invention as applied to a photoelectric musical instrument;

Figure 3 shows portions of a pitch disc and a timbre disc of another form in a photoelectric instrument; and

Figure 4 illustrates the manner' in which my I my invention may be applied to instruments having pitch determining elements disposed upon two pitch discs.

In Figure 1, I have shown in purely diagrammatic fashion the operating elements of a photoelectric device to which my invention, as later described, may be applied. Light from a source I is broken into a series of moving beams by slots 2 in a disc 3 which rotates at a fixed speed as determined by suitable driving means, such as a motor M. The beams, condensed as may be rethe musical intervals between the tones produced approximate those of the equally tempered scale, and wherein the number of elements, their sizes, and the distances between them are within practical considerations.

It is a further object to provide a relationship quired by a lens system 4, traverse a photocell 5. A shutter system, comprising a fixed element 6 having an aperture 1 and a movable element 8 actuated through suitable linkage members 9 and H) by a playing key ll, serves the dual function of permitting the beams to pass when a particular note is desired, and of confining the beams in such fashion that as soon as one beam completes its traverse of an integral number of wave form patterns l2, disposed upon a wave form pattern disc l3, concentric with the pitch disc 3, another beam begins to traverse the same group of wave form patterns.

The light source I may be controlled by a stop tablet 15 through a switch [8. The photocell 5 may be connected through an amplifier I! to a loud speaker It for the production of sound.

The instrument of Figure l is elementary only, for general explanatory purposes. A complete polyphonic device employing my invention will contain pluralities of keys, shutter mechanisms, and the like for the several notes, as well as pluralities of rows of elements 2 according to the present invention, as will be set forth below.

In Figure 2 an opaque pitch disc l9 has arranged thereon endless concentric rows or series of transparent slots 20, each row having a whole number of slots as indicated by the series of numbers shown in Figure 2 at the left end of the illustrated portion of the pitch disc 19. I have discovered that the series of twelve numbers from 116 through 219 have a relationship which very nearly approximates that of the twelve half tones of the equally tempered scale, which relationship will hereinafter be described in detail. Similar to Figure 1 the shutter mechanism of Figure 2 comprises a fixed element 2| having apertures 22 respectively aligned with the concentric rows of transparent slots 20. The central area of the portion of the pitch disc [9 is broken away to expose wave form patterns 23 and 24 which are disposed upon a timbre disc 25, which is also broken away for the purpose of showing the relationship between the angles subtended by individual cycles of the wave form patterns 23 and 24. A movable shutter member 26 is shown in an elevated position, similar to that of element 8 in Figure 1, exposing the aperture 22, through which can be seen three cycles of a wave form pattern and three corresponding slots of the pitch disc I9, illustrating the manner in which the patterns are scanned by the moving slots.

I shall now discuss the relationship of the slots 20 as mentioned above. Under the letter N in column I of the chart shown below I have listed the above mentioned series of twelve numbers, the relationship of which, according to my invention, approximates that of the equally tempered scale.

In the adjacent column II are listed the ratios N/116, thus referring to the lowest in the series. Adjacent to the N/l16 group is a column III of corresponding ratios of twelve half tones according to the equally tempered scale. The equally tempered, or equitempered, scale is of course the well known scale in almost universal use in which the pitches or frequencies of adjacent notes are in the ratio of the twelfth root of two to one, an incommensurate number. Consequently, the numbers in column III are in fact also incommensurate and only their accurate approxima tion can be given. Column IV lists the departures of numbers in column II from corresponding numbers in column III, in parts per 10,000.

I have found that the above departures of the I ratios according to my invention from the ratios of the equally tempered scale are sufficiently low to render such ratios wholly satisfactory to the ear for relating the quantities of pitch determining elements as mentioned above. It should also be noted that the whole numbers in my ratios are low enough so that elements of practical size may be disposed in rows, either circular or straight, of comparatively short length. As implied by the numbers indicated at the left of the pitch disc IS in Figure 2, integral multiples of the series of twelve numbers may be employed to carry the gamut of tones through more than one octave in exact octave relationships. For instance, if

,. the pitch disc I9 is rotated at a speed of 33.83

R. P. M. (revolutions per minute), so that the row containing 116 slots produces a note C in a musical scale having a frequency of 65.4 C. P. S. (cycles per second) based on a note of A of 440 C. P. S., the row containing 232 slots will produce a note C an octave above, having a frequency of 130.8 C. P. S. Similarly the row containing 246 slots will produce a C#- one octave above the C produced by the row containing 123 slots. In this way I can provide a complete musical scale of Center-to-center spacing of slots for (3:654

C. S .T Vs Radius to row of slots for C=2093 C. P.- S. 6 Center-to-center spacing of slots for 0:,2093

S- s-g1 1 Radial spacing between centers of adjacent rows of slots 1 According to my invention, I employ the same series of numbers to relate the angles subtended. by individual cycles of wave form patterns. For example, the angle A subtended by a single cycle of the wave form, pattern 24 will be related to the angle B, subtended by a single cycle or the wave form pattern 23, as the reciprocals of the numbers 2 l9 and I30, respectively, which indicate. the number of slots. in the rows respectively aligned with the wave form patterns.

Although I have shown herein wave form patterns of the variable area type, it is understood that I may also. employ variable density patterns well known in the art.

In the case of a photoelectric instrument employing a pitch disc and a timbre discwhich are' not mounted concentrically but overlap as shown in Figure 3, the wave form patterns 21 and 28,

disposed upon a timbre disc 29, will'subtend angles C and D, respectively,- having their respective apexes' at the center of the pitch disc 30. In such an instrument one tone color may be produced,

mining elements maybe accomplished in several ways. First, I may distribute the elements corresponding to alternate half tones on one disc, placing on the other disc those alternate pitch determining elements missing from the first disc. For example, rows on the first disc may contain 116, 130, 146, 164, 184 and 207, and/or integral multiples thereof, as desired, with elements in the following proportions on the second disc; 123, 138, 155, 174, 195 and 219. In this case the discs 3| and 32 of Figure 4 may be mechanically coupled by coupling 33 having 1:1 shaft ratio, or the discs may be mounted on the same shaft, if so desired. Also according to my invention I may employ two continuously moving members having members of pitch determining elements distributed thereon as determined by a series of alternate numbers, taken from the above series of twelve, in either of the following proportions: (a) 116, 130, 146, 164, 184, and 207 and/or integral multiples thereof; or (b) 123, 138, 155, 174, 195 and 219 and/or integral multiples thereof. In such a case, where the discs contain each the same numbers of elements in the several series, but in proportion to alternate semitones of the equitempered scale, it will be necessary that the shaft ratio produced by the coupling or speed reducer 33 be substantially the twelfth root of two to one. In yet another arrangement each of the discs 3| and 32 may contain identical series of pitch determining elements arranged as all of the semitones of one or more octaves, in which event the shaft ratio produced at 33 may be 2:1; 4:1, or other whole number ratio suitable for octave separation.

Although I have described my invention as applying to a photoelectric musical instrument employing rotary discs, I do not wish to be limited to such structures. M invention may be applied to photoelectric instruments employing drums, cones, or continuous bands; or it may be applied to instruments employing continuously moving members having thereon magnetic tracks, magnetic projections or any other pitch determining elements in endless rows which successively and continuously pass by a given point or points at rates which determine the pitch of the corresponding notes.

Modifications may be made in my invention without departing from the spirit of it; but having outlined the principles of the invention in certain exemplary embodiments, that which I claim as new and desire to secure by Letters Patent is:

1. In a musical instrument, a continuously moving member having a plurality of rows of musical pitch determining elements, said rows containing quantities of said pitch elements related to each other in proportions embraced in the following numbers: 116, 123, 130, 138, 146, 155, 164, 174, 184, 195, 207 and 219.

2. In a musical instrument, a continuously moving member having a plurality of rows of musical pitch determining elements, said rows containin respectively numbers of elements in the following proportions: 116, 123, 130, 138, 146, 155, 164, 174, 184, 195, 207 and 219.

3. In combination in a musical instrument, two continuously moving members having the same speed, and a plurality of rows of musical pitch determining elements disposed on said members, said rows on one of said members containing quantities of said pitch elements in the following proportions: 116, 130, 146, 164, 184 and 207, and said rows on the other of said members containing quantities of said pitch elements in the following proportions: 123, 138, 155, 174, 195, and 219.

4. In combustion in a musical instrument, two continuously moving members having a speed ratio of substantially the twelfth root of twoto one, a plurality of rows of musical pitch determining elements disposed on both said members, said rows on both said members containing quantitles of said pitch elements in the following proportions: 116, 130, 146, 164, 184 and 207.

5. In combination in a musical instrument, two continuously moving members having a speed ratio of substantially the twelfth root of two to one, a plurality of rows of musical pitch determining elements disposed on both said members, said rows on both said members containing quantities of said pitch elements in the following proportions: 123, 138, 155, 174, and 219.

6. In a photoelectric musical instrument, a continuously rotating disc having concentric rows of musical pitch determining, light varying areas, said rows containing said areas in the following proportions: 116, 123, 130, 138, 146, 155, 164, 174, 184, 195,207 and 219.

7. In a photoelectric musical instrument, two opaque discs continuously rotating with substantially the same angular velocity, said discs having endless concentric rows of musical pitch determining, light varying areas, said rows on one disc containing quantities of said areas in the following proportions: 116, 130, 146, 164, 184 and 207, said rows on the other disc containing quantitles of said areas in the following proportions: 123, 138, 155, 174, 195 and 219.

8. In a photoelectric musical instrument, two opaque discs continuously rotating with angular velocities having a ratio of substantially the twelfth root of two to one, there being musical pitch determining, light varying areas disposed upon said discs in endless concentric rows, said rows having quantities of said areas in the following proportions: 116, 130, 146, 164, 184 and 207.

9. In a photoelectric musical instrument, two opaque discs continuously rotatin with angular velocities having a ratio of substantially the twelfth root of two to one, there being musical pitch determining, light varying areas disposed upon said discs in endless concentric rows, said rows having quantities of said areas in the following proportions: 123, 138, 155, 174, 195 and 219.

10. The method of relating the frequencies of twelve oscillations to provide substantially the musical intervals of an equally tempered scale, which method consists in relating said frequencies respectively in the following proportions: 116, 123, 130, 138, 146, 155, 164, 174, 184, 195, 207 and 219.

11. In a. photoelectric musical instrument, an opaque pitch disc having transparent slots disposed thereon in endless concentric rows in quantities proportioned as follows: 116, 123, 130, 138, 146, 155, 164, 174, 184, 195, 207 and 219, and a timbre disc located adjacent to said pitch disc, said timbre disc having a series of wave form patterns respectively aligned with said rows, each said pattern representin an integral number of cycles of a wave, each cycle of a particular pattern subtending an angle equal to 360 divided by the number of slots in the row aligned with said particular pattern.

12. In a musical instrument of the type wherein a photosensitive device is traversed by a series tively to the pitch of notes of a musical scale, a timbre disc and a series of Wave form patterns disposed thereon, each pattern representing at least one cycle of a wave, the angles subtended by single-cycle portions of respective patterns of the series being related as the reciprocals of the following numbers: 116, 123, 130, 138, 146, 155, 164,,

174, 184, 195, 207 and 219. v

13. In combination in a musical instrument, a plurality of moving members each having a plurality of rows of musical pitch determining elements, said rows containing respectively humbers of elements in the following proportions:

116, 123, 130, 138, 146, 155, 164, 1'74, 184, 195, 20'? and 219 and means for moving said'memhers in whole number speed ratios.

ARMAND F. KNOBLAUGH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,998,461 Kucher Apr. 23, 1935 2,014,741 Lesti Sept. 17, 1935 2,075,802 Davis 1 Apr'. 6, 1937 

